Faraday Technology Corporation

Sheng-Hua Chen

Jeng-Huang Wu

Hung-Yi Chang

Cheng-Hsing Chien

Yu-Hao Liu

Chiang-Hsiang Liao

Chih-Wen Yang

A true single-phase clock (TSPC) D flip-flop includes four stages. The four stages are serially connected between the input terminal and the output terminal of the TSPC D-type flip-flop. Each stage is selectively equipped with two connecting devices. One of the two connecting devices is a resistive element. The other of the two connecting devices is a short circuit element. When the node between two stages is in the floating state, the voltage change is slowed down by the resistive element. Consequently, the possibility of causing the function failure of the D-type flip-flop is minimized.

D flip-flop

A flip-flop circuit including a first logic circuit, a first master latch, a second master latch, and a slave latch is provided. The first logic circuit operates a logic operation on a selecting signal and a clock signal to generate a first control signal. The first master latch receives a data signal according to the first control signal and latches the data signal according to the selecting signal and the clock signal. The second master latch receives a scan data signal according to the selecting signal and the clock signal, wherein an output terminal of the second master latch is directly connected to an output terminal of the first master latch. The slave latch latches a signal on the output terminals of the first and second master latches for generating an output signal.

Flip-flop circuit

A level shifter includes a Not gate coupled to a signal input and operable between a first high level and a low level; a first PMOS transistor coupled to a second voltage source and a control end; a first NMOS transistor coupled to the first PMOS transistor, a Not-gate output end and a reference voltage; and a control circuit coupled to the signal input, the Not-gate output end and the second voltage source. When the signal input and the Not-gate output end are at the first high level and the low level, respectively, the first PMOS transistor is turned on so that the signal output is at a second high level; and when the signal input and the Not-gate output end are switched contrarily, the first PMOS transistor is turned off and the signal output is at the low level.

Level shifter with reduced power consumption and low propagation delay

A Schmitt trigger includes A first PMOS transistors having the drains and sources thereof serially connected and coupled between a voltage source and an output end, and having gates thereof coupled to an input end; B first NMOS transistors having the drains and sources thereof serially connected and coupled between the output end and ground, and having gates thereof coupled to the input end; C second PMOS transistors, each being coupled between ground and a node between the drain and the source of the first PMOS transistors and having the gate thereof coupled to the output end; and D second NMOS transistors, each being coupled between the voltage source and a node between the drain and the source of the first NMOS transistors and having the gate thereof coupled to the output end. A is greater than 2 and C, and B is greater than 2 and D.

Schmitt-trigger-based level detection circuit

A CMOS Pierce crystal oscillator. A clock generator with activation control, for generating a clock signal. The clock generator comprises an amplifier, a shaping circuit and a diagnostic circuit. The amplifier is capable of being coupled to an external oscillation source through an input pad and an output pad to generate an oscillating signal, the shaping circuit is capable of being coupled to the output pad, for shaping the oscillating signal to generate a clock signal, and the diagnostic circuit is capable of being coupled to the output pad, for asserting a ready signal when amplitude of the oscillating signal exceeds a predetermined portion of a full swing voltage.

Crystal oscillator circuit with activation control

An input/output buffer protection circuit, which comprises an I/O pad, an I/O buffer, an n-well control circuit, a gate control circuit, and a protection component. The I/O buffer includes a PMOS transistor and a NMOS transistor. The n-well control circuit is coupled to an n-well of the PMOS transistor. When an input voltage higher than a source voltage is applied, voltage at the n-well of the PMOS is increased by the n-well control circuit to the input voltage level. The gate control circuit is coupled to the gate terminal of the PMOS transistor and the input/output pad. When an input voltage higher than a source voltage is applied, voltage at the gate terminal of the PMOS is increased by the gate control circuit to the source voltage level. Wherein the gate control circuit comprises a transistor and the transistor transfers a high potential control voltage to the gate of the PMOS transistor in output mode. The protection component is coupled between the gate of the transistor and the I/O pad to generate a voltage drop down path and block the I/O pad signal from flowing back to the gate of the transistor.

Input/output buffer protection circuit

An input/output buffer. An input/output circuit has a transmission terminal coupled to an I/O pad, and a floating N-well region. A P-gate control circuit conveys the second gate control signal to the gate of the first PMOS transistor. A feedback detection device is coupled between the transmission terminal and an N-well control circuit to output a feedback signal according to an input voltage at the I/O pad. The N-well control circuit adjusts the voltage level at the N-well region of the first PMOS transistor according to the feedback signal output from the feedback detection device.

Input/output buffer

An input/output buffer. An input/output circuit is composed of a first PMOS transistor and a first NMOS transistor, has an I/O port coupled to an I/O pad, and a N-well region. An N-well control circuit controls the voltage level at the N-well region of the first PMOS transistor according to input signals at the I/O pad. A P-gate control circuit receives a second gate control signal and outputs to the gate of the first PMOS transistor. The P-gate control circuit is composed of a transmission gate and a third PMOS transistor. The transmission gate and the third PMOS transistor do not have to follow the design rule for ESD, and the wafer area required for the P-gate control circuit can be decreased because the P-gate control circuit is not directly connected to the I/O pad.

Growing community of inventors

Kaohsiung, Taiwan

Sheng-Hua Chen